First characterization of the cooling of the paleo-geothermal system of Terre-de-Haut (Les Saintes archipelago, Guadeloupe): Application of fluid inclusion and chlorite thermometry

2021 ◽  
pp. 107370
Author(s):  
Gildas Beauchamps ◽  
Franck Bourdelle ◽  
Michel Dubois ◽  
Ronan Hébert ◽  
Béatrice Ledésert
Keyword(s):  
Fluid Inclusion ◽  
Geothermal System ◽  
Les Saintes

scholarly journals Mineralogical and Fluid Inclusions Study of Epithermal Type Veins Intruding the Volcanic Rocks of the Kornofolia Area, Evros, NE Greece.

2019 ◽  
Vol 55 (1) ◽  
pp. 202
Author(s):  
Foteini Aravani ◽  
Lambrini Papadopoulou ◽  
Vasileios Melfos ◽  
Triantafillos Soldatos ◽  
Triantafillia Zorba ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Fluid Inclusion ◽  
Hydrothermal Alteration ◽  
Fluid Inclusions ◽  
Volcanic Rocks ◽  
The Other ◽  
Calc Alkaline ◽  
Ft Ir ◽  
Host Rocks

The volcanic rocks of Kornofolia area, Evros, host a number of epithermal-type veins. The host rocks are Oligocene calc-alkaline andesites to rhyo-dacites. The andesites form hydrothermal breccias and show hydrothermal alteration. The veins comprise mainly silica polymorphs such as quartz, chalcedony and three types of opal (milky white, transparent and green). Amethyst also forms in veins at the same area. Apart from the silica polymorphs, the veins are accompanied by calcite and zeolites. The main aim of this study is the characterization of the silica polymorphs. Using FT-IR analyses, variations in the crystal structure of the three opals were recognized. The green opal is found to be more amorphous than the other two types. Fluid-inclusion measurements were performed in calcite and were compared with amethyst from previous studies. The Th is between 121-175 °C and the Te between -22.9 and -22.4 °C. The salinities range from 0.9 to 4.5 wt % NaCl equiv.

scholarly journals LA-ICP-MS U-Pb dating and geochemical characterization of oil inclusion-bearing calcite cements: Constraints on primary oil migration in lacustrine mudstone source rocks

2021 ◽  
Author(s):  
Ao Su ◽  
Honghan Chen ◽  
Yue-xing Feng ◽  
Jian-xin Zhao
Keyword(s):  
Fluid Inclusion ◽  
Inductively Coupled Plasma ◽  
Homogenization Temperature ◽  
Source Rocks ◽  
Oil Migration ◽  
Carbon And Oxygen Isotope ◽  
Fluorescence Characteristics ◽  
Calcite Veins ◽  
Migration Event

To date, few isotope age constraints on primary oil migration have been reported. Here we present U-Pb dating and characterization of two fracture-filling, oil inclusion-bearing calcite veins hosted in the Paleocene siliciclastic mudstone source rocks in Subei Basin, China. Deposition age of the mudstone formation was estimated to be ca. 60.2−58.0 Ma. The first vein consists of two major phases: a microcrystalline-granular (MG) calcite phase, and a blocky calcite phase, each showing distinctive petrographic features, rare earth element patterns, and carbon and oxygen isotope compositions. The early MG phase resulted from local mobilization of host carbonates, likely associated with disequilibrium compaction over-pressuring or tectonic extension, whereas the late-filling blocky calcite phase was derived from overpressured oil-bearing fluids with enhanced fluid-rock interactions. Vein texture and fluorescence characteristics reveal at least two oil expulsion events, the former represented by multiple bitumen veinlets postdating the MG calcite generation, and the latter marked by blue-fluorescing primary oil inclusions synchronous with the blocky calcite cementation. The MG calcite yields a laser ablation−inductively coupled plasma−mass spectrometry U-Pb age of 55.6 ± 1.4 Ma, constraining the earliest timing of the early oil migration event. The blocky calcite gives a younger U-Pb age of 47.8 ± 2.3 Ma, analytically indistinguishable from the U-Pb age of 46.5 ± 1.7 Ma yielded by the second calcite vein. These two ages define the time of the late oil migration event, agreeing well with the age estimate of 49.7−45.2 Ma inferred from fluid-inclusion homogenization temperature and published burial models. Thermodynamic modeling shows that the oil inclusions were trapped at ∼27.0−40.9 MPa, exceeding corresponding hydrostatic pressures (23.1−26.7 MPa), confirming mild-moderate overpressure created by oil generation-expulsion. This integrated study combining carbonate U-Pb dating and fluid-inclusion characterization provides a new approach for reconstructing pressure-temperature-composition-time points in petroleum systems.

scholarly journals FLUID GEOCHEMISTRY INVESTIGATIONS ON THE VOLCANIC SYSTEM OF METHANA

2007 ◽  
Vol 40 (2) ◽  
pp. 712
Author(s):  
W. D'Alessandro ◽  
L. Brusca ◽  
K. Kyriakopoulos ◽  
M. Margaritopoulos ◽  
G. Michas ◽  
...  
Keyword(s):  
Geothermal System ◽  
Volcanic System ◽  
Spatially Correlated ◽  
Co2 Output ◽  
Active Tectonic ◽  
Soil Site ◽  
Gas Hazard ◽  
Tectonic System ◽  
Cold Groundwaters

An extensive geochemical survey on the fluids released by the volcanic/geothermal system of Methana was undertaken. Characterization of the gases was made on the basis of the chemical and isotopie (He and C) analysis of 14 samples. CO2 soil gas concentration and fluxes were measured on the whole peninsula at more than 100 sampling sites. 31 samples of thermal and cold groundwaters were also sampled and analysed to characterize the geochemistry of aquifers. Anomalies referable to the geothermal system, besides at known thermal manifestations, were also recognized at some anomalous degassing soil site and in some cold groundwater. These anomalies were always spatially correlated to the main active tectonic system of the area. The total CO2 output of the volcanic system has been preliminary estimated in about 0.2 kg s~ . Although this value is low compared to other volcanic systems, anomalous C02 degassing at Methana may pose gas hazard problems. Such volcanic risk, although restricted to limited areas, cannot be neglected and further studies have to be undertaken for its better assessment.

Characterization of a geothermal system in the Upper Arkansas Valley, CO

2009 ◽  
Author(s):  
Thomas Blum ◽  
Kasper van Wijk ◽  
Lee Liberty ◽  
Michael Batzle ◽  
Richard Krahenbuhl ◽  
...  
Keyword(s):  
Geothermal System

A FLUORESCENCE CONTRIBUTION TO THE RECOGNITION OF FLUIDS TRAPPED IN MINERALS IN THE CARPATHIAN OUTCROPS

2019 ◽  
Vol 474 (474) ◽  
pp. 7-22
Author(s):  
Katarzyna JARMOŁOWICZ-SZULC
Keyword(s):  
Organic Matter ◽  
Fluid Inclusion ◽  
Point Of View ◽  
General Distribution ◽  
The West ◽  
Thin Sections ◽  
Fluorescence Studies ◽  
Analytical Tools ◽  
Inclusion Methods

Based on the assumption that fluorescence studies are an important tool in search and characterization of hydrocarbons, samples of rocks, minerals and the organic matter were collected in the Western Carpathian area spreading from the Mszana Górna region in the west to the Bieszczady Mts. in the east, and continuously, towards SE outside the Polish frontier, in Ukraine and Slovakia. Analytical procedures comprised preparation, microscopic observation of the material (organic matter and minerals) from the point of view of inclusions and fluorescence followed by detailed luminescence studies. Those steps have been followed by the microthermometric determinations. The application of the fluid inclusion methods, which are one of the newest analytical tools in the last two decades have led to the characteristics of fluids trapped in the inclusions in the area. The fluorescence studies showed some diversity of hydrocarbons both in compositions and in distribution. The analyses were performed in double-sided polished thin sections prepared based on cold techniques. Fluorescence of inclusions in two minerals, quartz and calcite, was checked in those specific thin sections either in glued wafers, or loose (single) crystals. The fluid inclusion studies were accompanied later on by solid organic matter inclusion studies. Those point to the presence of the following minerals: quartz, dolomite, calcite, clay minerals, gypsum with anhydrite admixture, traces of pyrite and siderite, feldspars. General distribution of fluorescing and not fluorescing inclusions suggests the presence of light hydrocarbons (methane) in the west and south of the area, being enriched in higher hydrocarbons (oil) towards the east.

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